1. Field of the Invention
This application pertains generally to elevated walking devices involving user translation, commonly referred to as stilts, and more particularly to articulating stilts having a rear leg brace. The present invention provides a natural bio-mechanical motion that has been unattainable in the prior art.
2. Description of the Related Art
The concept of stilts is a very old one, predating the United States patent system. Illustrating this is U.S. Pat. No. 31,210 to Johnson, simply entitled “Stilt,” dating back to January, 1861. This patent is clearly not the first conception of stilts, but is instead an improvement thereto. At the time of this patent, this stilt simply provided a foot rest or step onto which a user would stand, without any straps or bindings holding one's shoes thereto, and with hand-held braces extending up the outside of each stilt.
As might be expected from such an old technology, there have over the years been a wide variety of improvements, and an associated increase in applications to which the benefits of stilts have been applied. One application from earlier times is believed to have been simply that of improved transportation, through both wetlands and also above troublesome low-lying flora and fauna. Through the years, and beyond entertainment with which most people are familiar, many other diverse applications have evolved. There are many agricultural applications, including the gathering of fruits and nuts, the pruning of trees, and improved viewing of flocks. Construction applications have likewise developed, including the use of stilts with drywall finishing, painting, electrical and plumbing work, window washing, and ceiling installation and repair. There have been many other diverse applications too numerous to mention where the additional elevation afforded by stilts has or might prove to be highly desirable.
One patent which is particularly exemplary of the improvements that have been made to stilts is U.S. Pat. No. 3,902,199 to Emmert, the teachings which are incorporated by reference. The Emmert patent illustrates one particular stilt design which has met with much long term commercial success. Therein, an articulating stilt is illustrated. For the purposes of the present specification, an articulating stilt will be understood to mean a stilt which permits a variation in the angle between a line drawn between the toe and heel of the stilt and the vertical risers, and which couples this variation in angle to a boot engaging member or members, such that the wearer will have an ability to both sense and through natural movement control the variation of this aforementioned angle. Through the linkages illustrated and taught by Emmert, a wearer has the ability to pivot their foot and the stilt foot in a natural motion during forward and backward movement. It is, for example, possible to remove all weight from the heel portion, and stand entirely on the toe portion of the stilt. This articulating motion allows substantially greater control and balance than achieved with other stilt designs.
The Emmert stilt provides much more sensory feedback and control than those of the prior art, and as a result has become a standard in the industry today. Others have attempted to improve upon this concept, using such techniques as the combination of a prosthetic foot with a leg support apparatus, or various spring feet or the like. Instead, the industry has continued with the articulated stilt, owing to the better sense and natural movement. A large number of patents are representative of this adoption, including U.S. Pat. Nos. 4,570,926 and 5,498,220 to Ensmenger; U.S. Pat. No. 6,517,586 to Lin; U.S. Pat. No. 6,648,803 to Jay; published application 2002/0077704 to Lin; published application 2003/0203793 to Emmert; published application 2005/0202940 to Simmons; published applications 2006/0217241 and 2007/0027004 to Novara; published application 20070167296 to Hika; and U.S. Pat. No. D359,313 to Hashman; the teachings of each which are incorporated herein by reference.
The present inventor has discovered a deficit in the prior art articulated stilts. Each of these prior art stilts uses either a single side-mounted leg brace, or a pair of opposed side-mount braces for each stilt. When a single side-mounted leg brace is used on a stilt, the brace extends adjacent the outer part of the wearer's leg, distal to a leg brace on the other stilt. In other words, a stilt for the left leg will have a leg brace extending to the left of the wearer's leg, while a stilt for the right leg will have a right leg brace extending to the right of the wearer's leg. This placement of leg braces has been the standard at least since the time of the Johnson U.S. Pat. No. 31,210 referenced herein above, from January, 1861.
The present inventor has discovered that side placement of the brace produces very undesirable torque upon the leg of a user during ordinary movement. As a wearer steps forward with one leg, the leg brace will at different times in the motion engage and apply force upon the user's lower leg. This force is not in line with the forward leg movement, and so will produce a distinct twisting or torque upon the user's leg. That torque is one of the factors that requires compensation by the user, in the form of muscle movement that is not otherwise a part of ordinary walking or striding. Without muscular compensation, the stilts will undesirably move in a direction out of in-line with the stride, and will also tend to rotate or wobble undesirably, either of which may also produce a very undesirable tumble.
The two opposed side-mount braces avoid this deficiency. However, where the articulated stilt uses two opposed side-mount braces per stilt, the wearer has two braces running between his legs, and as he steps forward or backward, these braces are easily conflicting. It may be apparent that, should these inner braces from different stilts collide, the user may inadvertently and undesirably fall. In addition, the use of two braces increases the parts required, and undesirably increases the weight and cost of the stilt.
A few artisans have attempted other placement of the leg brace, on non-articulating stilts. Exemplary of these are U.S. Pat. No. 642,841 by Freshour; U.S. Pat. No. 2,827,897 by Pawlowski; U.S. Pat. Nos. 5,295,932 and 5,514,054 to Rowan; U.S. Pat. No. 6,719,671 by Bock; and U.S. Pat. No. 6,840,893 by Yoon; the teachings of each which are incorporated herein by reference. These non-articulating stilts do not offer the sensory feedback or natural movement and control afforded by articulating stilts, and so have not been well accepted in the marketplace.
A number of other types of stilts are known and represented in the prior art. Exemplary patents include U.S. Pat. No. 4,255,822 to Dixon; U.S. Pat. No. 4,415,063 to Hutchinson; U.S. Pat. No. 5,016,869 by Dick et al; U.S. Pat. No. 5,593,373 to Hale; and French patent 2,620,345 to Champel; the teachings of each which are incorporated herein by reference.
In spite of the capabilities that are afforded through these stilts or leg extensions, an important issue has always been and continues to be that of safe use. As is well known, the additional height that the stilts provide is the feature that makes stilts desirable in many applications, but is also the feature that makes falls far more dangerous. Falls from only somewhat greater heights are disproportionately more hazardous. In addition, the extra length provided by the stilts in association with the coupling between person and stilts at only a few discrete places may also place unusual forces upon the leg that can lead to strains, sprains and fractures that are both different from and frequently more severe than could occur without the stilts. Finally, a wearer has no sensitivity at the extremity, which is quite unlike a living foot containing many active sensory nerves. Consequently, electrical cords, ropes, wires, uneven surfaces, and other obstacles and challenges may adversely affect the ability of a person to step properly and might then lead to a spill. In view of the direct correlation of harm with a fall where a person was wearing stilts, the chances of problems have heretofore been believed to be greater with stilts than without. As a result, the use of stilts has been effectively eliminated in the workplace in several states.
The banning of stilts in the workplace is surprising when the alternatives to stilts are considered. For exemplary purposes, in the construction trade the use of a ladder is extremely inefficient. A worker may only reach a few feet in each direction from the ladder without unbalancing the ladder and potentially tipping it. On uneven or irregular surfaces, the ladder may even initially be unbalanced, not standing correctly on all four feet. A worker trying to reach too far in any direction while on a ladder, including but not limited to climbing to the top of a ladder, is known to be the cause for many construction injuries. To expand reach and elevation, while still avoiding the use of stilts, other workers rely instead upon portable scaffolding. This scaffolding requires significant set-up and take-down time, and the scaffolding itself may have significant mass or weight. The disassembly and movement of such scaffolding is, in and of itself, a common cause of workplace injuries. The need for more natural and more readily controlled stilts is therefore well established in the industry, and the present stilts do not fully address the need.
What is desired then is a way to best ameliorate the deficiencies of prior art stilts, such that the risks of use are less than the risks associated with alternatives, so that the use of stilts may be applied to all situations where stilts are inherently more efficient than the alternatives.